Method of applying an improved match striking surface



y 4, 1967 A. R. M MULLEN ETAL 3,329,521

METHOD OF APPLYING AN IMPROVED MATCH STPIKING SURFACE Filed Feb. 16, 1965 3 Sheets-Sheet 1 INVENTORS ALAN R. McMULLEN BY DONALD H. WILSON ATTORNEY Fig.

y 4, 1967 A. R. M MULLEN ETAL 3,329,521

METHOD OF APPLYING AN IMPROVED MATCH STRIKING SURFACE Filed Feb. 16, 1965 3 Sheets-Sheet B INVENTORS ALAN R. McMULLEN g BY DONALD H. WILSON ATTORNEY y 1967 A. R. MCMULLEN ETAL 3,329,521

METHOD OF APPLYING AN IMPROVED MATCH STRIKING SURFACE Filed Feb. 16, 1965 3 Sheets-Sheet 5 INVENTORS ALAN R. MCMULLEN BY DONALD H. WILSON ATTORNEY United States Patent 3,329,521 METHOD OF APPLYING AN IMPROVED MATCH STRIKING SURFACE Alan R. McMullen and Donald H. Wilson, Wadsworth,

Ohio, assignors to Hunt Foods and Industries, Inc., Fullerton, Calif., a corporation of Delaware Filed Feb. 16, 1965, Ser. No. 433,030 7 Claims. (Cl. 117-38) called, striking surface) having adequate quality, economy of manufacture, wear (e.g., with sufficient thickness and with the absence of pronounced hills and valleys) and good definition (for both artistic and mechanical reasons, as later explained herein).

For either safety (e.g., book or penny box) matches or strike-anywhere (i.e., kitchen) matches, if the binder of the friction is a Water soluble glue or natural gum (e.g., gum arabic) then when striking surface gets Wet it will stain clothing and often will not light matches. As a consequence, the art has turned to synthetic resin binders of one type or another but it still has usually mixed the binders with water (like a latex house paint) and, according to the prior art, the friction was then applied by a wheel, or a brush or by extrusion, to ultimately provide the friction material on paperboard covers for book matches or on slides for kitchen match boxes. Still the degree of water insolubility and moisture resistance usually has not been complete.

While it is true that in some instances completely water insoluble friction has been known in the past (for example, see United States Patent 2,683,098), such material has not heretofore been universal but has, rather, been limited to use with kitchen matches and not suitable for use on safety match books (even with a phosphorous igniter added) because of slickness. Additionally, all the prior art compositions are not suitable for application to paperboard container surfaces by any except the prior art methods which result in poor definition.

In connection with definition (e.g., resolution of edge demarcations) it should be noted that friction of the type described is not generally applied to individual containers for matches but rather, for production economy, to roll, sheet or large card stock from which the individual containers are later cut. With the friction compositions and processes heretofore known, there has then existed a production problem because the friction material rapidly dulls knives and shear blades later used to cut up the cards, sheets or roll stock. With prior compositions and processes this could, apparently, not be avoided because the wheel, brush, and extrusion techniques did not lend themselves to providing adequate definition so as to permit missing ultimate cut lines when laying on the friction during an economically requisite high speed continuous printing process.

It is an object of the present invention to provide simple and inexpensive means for overcoming the above mentioned difiiculties.

Other objects and advantages will become apparent and the invention may be better understood from considera tion of the following description taken in connection with the accompanying drawings.

In broad aspect, we meet the objects of the invention by providing a novel friction composition and we apply this composition in novel manner, with a rotogravure press. This involves not only the novel formulation of friction compound but also a change in screen size, in etch depth, and in cell to wall ratio as contrasted with those known in printing presses heretofore, and the combination of all of these factors results in more artistic work, in large cost savings, and in good wearing qualities of the friction due to the uniformity of its thickness.

In the drawings:

FIG. 1 is a perspective front and side elevation view of a rotogravure press-line used for printing a substantially continuous web of paperboard stock as fed from a roll (not shown);

FIG. 2 is a simplified or schematic side view of the friction applying rotogravure press station which is indicated generally at 13 in FIGS. 1 and 2;

FIG. 3 is an enlarged and developed (flattened out) view of a portion of a printing cylinder 15 (see FIG. 2) sleeve 17;

FIG. 4 is a transverse section of the developed sleeve 17 as viewed along the line 44 in FIG. '3;

FIG. 5 shows an intermediate product, namely a portion of a printed web; and

FIG. 6 shows a finished match'book provided with a striking surface in accordance with the invention.

Referring to FIG. 1, a machine base 10 supports six separate (e.g., each for a different color) rotogravure press stations 11 through which a paperboard stock 12 (assumed used for making book match covers) sequentially passes. Next, the stock 12 passes through a printing station 13 which is a friction applying station and which, in accordance with the present invention, is a rotogravure press station. As is well known, rotogravure is characterized by printing from recesses rather than from raised (letter press) or coplanar (offset) image areas.

It is preferable that the friction applying station be the last of the rotogravure stations following those in which the more conventional (decorative or advertising) rotogravure col-or printings of lesser depth are applied to the stock.

The path of the stock through each station may be the same but only the new friction applying rotogravure station is of interest in connection with the present invention, and, as schematically shown in FIG. 2, here the stock ,12 may follow the path shown dashed at 12', first passing under two guides rollers 14, then over a third and then between a printing cylinder 15 and an impression cylinder 16. The impression cylinder presses the paperboard in contact with friction composition located in cells upon a sleeve 17 provided on the printing cylinder 15. In conventional manner (except for the novelty of the fluent) a pump or fountain 18 supplies friction 19 to the printing cylinder sleeve 17, and doctor blades 20 serve to remove excess friction and return it to the fountain. Conventional drying means (not shown) is assumed included under an oven hood 21. Additional drying means can be added on down the runout line, in the direction of stock travel, which is as indicated by the arrow T in FIGS. 1 and 2.

For a better understanding of various aspects of the invention the friction composition will next be described. In order to have a suitable match striking friction which can be rotogravure applied, the many obstacles include (1) dried film thickness (desirably about twenty times as thick as films heretofore rotogravure applied), (2) drying time (because of the desirable high speed of the press, very fast drying is desired), (3) viscosity (thick enough to hold in the cells against centrifugal force, thin enough to go in the cells and thin enough to later spread to cover the wall areas during drying, to prevent hills and valleys in final friction, and thick enough to provide good definition). To meet these requirements we found that the coating composition should be a non-aqueous solvent base friction (instead of having a Water base) despite the fact that solvent frictions had never previously shown completely satisfactory striking characteristics. We found that the composition should have an initial (before drying) viscosity of to 35 seconds #4 Zahn cup at 70 F., and, when dried, a substantially uniform thickness falling within the range of .001 to .003".

To meet these and other criteria the solids content of our proposed friction composition may have (by weight of total solids) to 50% acrylic resin binder, 0 (e.g., for strike anywhere matches) to 75% (e.g., upper limit for safety matches) igniter, and may have conventional solid additives such as 0 to 8% filler, 0 to color pigment, 0 to 10% dispersant, and 0 (for safety matches) to 75% (for strike anywhere matches) abrasives such as silica flour, ground glass or pumice. Preferably, however, the abrasive content will be kept at the lowest tolerable percentage in order to lengthen rotogravure cylinder sleeve life and avoid the expense of going to expensive (and hard to etch) stainless steel for the printing cylinder sleeve.

As contrasted with the prior art, there is a difference in the binder. The above mentioned Sinks patent, for example, suggests the use of a maleic anhydride resin which, while suitable for the purposes Sinks had in mind, would not be satisfactory for providing a usable (not too slick) friction layer on book matches, would not be suitable for rotogravure application, would not be suitable for forming a substantially uniform thickness friction layer (without costly hills and poor wearing valleys), and would not be suitable for use to provide a layer of suitable thickness (e.g., .001 or .002 or .003" thick) without wearing through on safety match books.

In accordance with the present invention, a binder is provided which is not only soluble in organic solvents but is tough, does not tend to promote settling of pigments or other solids, does not tend to give undesired slickness in final friction.

For the binder an acrylic resin is preferred. The polymethyl acrylate resins, such as that obtainable under the trade name Acryloid B66 (copolymer of methyl meth acrylate and butyl acrylate) has given excellent results. Other acrylic polymer binders are also usable, for example those obtainable under the trade names of Lucite (methyl methacrylate) and Acryloid B-82 (copolymer of methyl methacrylate and ethyl acrylate). Acrylic ester polymers are also satisfactory. By the use of such polymeric resin binders, we are able to achieve a relatively inexpensive, very suitable friction, particularly adapted to our novel (rotogravure) method of application to container surfaces. Preferred range of binder is from 25 to 50% of the solid content of the friction composition.

For the igniter, required for lighting safety matches, a conventional material such as red phosphorous is used, and the igniter Weight percent is at least 70% that of the binder but, depending on exact nature of binder, it can be much more.

Optionally, a solid filler such as diatomaceous earth may be added.

By the words color pigment we mean to include both pigments giving natural colors (e.g., blue ink solids) and a pigment such as carbon black which results in the friction being devoid of color (being black).

A suitable dispersant is the solid aluminum stearate. The following illustrate preferred coating compositions:

Example I.-F0r book matches Solids: Approximate parts by wt. Binder 32.5 Igniter 61 Pigment (carbon black) 4.5 Dispersant 2 Thinners:

Solvent (toluol) 69 Diluent (ethyl acetate) 3.5

Example Il.F0r strike anywhere matches Solids: Approximate parts by wt. Binder 41 Abrasive 46 Pigment (blue ink solids) 10 Dispersant 3 Thinner(s):

Non-aqueous thinner means 72 The thinner or thinners preferably have no water content. Suitable organic solvents or diluents are usual ones, e.g., acetone, and methyl ethyl ketone, besides those listed in Example I. In any event, the initial viscosity of the friction paint, which depends to some extent on the organic solvent and/ or diluent actually used, is permitted to vary, due to the organic solvent system, but only within our preferred limits of 10 to 35 seconds #4 Zahn cup at 70 F. The #4 Zahn cup is a relatively large one and, in general, the above mentioned limits dictate an initial solids to thinner ratio of at least one to one. Most desirably the viscosity is 12 sec. #4 Zahn at 70 F.

A suitable mixing procedure is to disperse the resin binder in cold toluol and then heat to F. with high speed mixing for one hour. Cool to room temperature, dilute further with ethyl acetate and then disperse aluminum stearate and carbon black. Then disperse amorphous red phosphorous and, if the need remains, finally dilute to desired viscosity.

The initial (before drying) viscosity of the composition and depth and width, etc., of the rotogravure intaglio etchings are part and parcel of the same problem which is to have the friction film flow to some extent but not too much. Referring now to FIGS. 3 and 4 we have shown developed views of the printing sleeve 17. As is well known there may be used (though not shown) a wire screen (usually much more than 100 mesh but in accordance with the present invention With only about 35 lines per inch, in both of two transverse directions) and photo-chemical processes which provide rotogravure image areas which are recessed as cells. Such cells are indicated as 32 in FIGS. 3 and 4. Actually, initial screen wires (or other mask lines) and holes need not exactly correspond to final Walls and cells respectively. For one thing, just which are resist and which are finally etched portions can depend upon the actual photo-chemical or other process used, and, because of etching, final walls may be thinner than original mask definitions. Moreover, the walls usually taper (providing cells which are V or U (see FIG. 4) shaped in cross section), but as such dimensions are referred to hereinafter, and in the appended claims, we refer to Cell Wall Thickness and Cell Width in the image area and in the plane of the large mouths of the cells. As seen in FIGS. 3 and 4 the cells 32 are separated by walls 33, and there results the dimensions of Cell Depth (indicated as CD in FIG. 4), Wall Thickness (WT) and Cell Width (CW). Our dimensions are, we believe, quite different from those generally known for image areas for rotogravure, as may best be shown by the table which follows:

R 1 to not less than 5.

For clarity the drawing FIG. 4 is not to scale (CW being preferably about 1"/35=.03", while CD is preferably about .008") but in any event we provide cavities and composition which provide suflicient flow to give desired dried film thickness (and to spread to cover wall areas after the walls have departed) even though the ink is of a viscosity much different from any rotogravure ink (or friction composition) heretofore used.

Of criticality then, is the amount of thinner. Of further criticality is the amount of binder (too little and other necessary solids come off during striking, too much and matches wont light). Also of criticality are the rotogravure dimensions and ratios discussed above.

One advantage of the composition thickness (plus nature of the thinners) is quick oven drying to adapt the materials and processes to the high speed advantages of the rotogravure. Another advantage is best illustrated by referring next to FIGS. 5 and 6.

FIG. 5 shows, as an intermediate product, a portion of a printed web 12". This stock may be later slit into four card widths 51 (e.g., 4%" wide) and cut into numerous card lengths 52 (e.g., each 16 /2 long). Each card may then be cut to provide eight (king-size) matchbooks. Optionally a portion of printed web could be cut into other card lengths for ultimately providing plural standard size match books or slides for covering boxes for either safety or strike-anywhere matches.

During the printing the multicolor printing stations 11 (FIG. 1) have produced artistic and/ or advertising printed areas which, for simplicity, we have designated by blocks 53 in FIG. 5. During the printing, press 13 (FIG. 1 or 2) has also produced the friction areas 54. These differ from friction areas (striking surfaces) on cards" heretofore because by use of apparatus, processes and compositions according to the present invention, much better definition is possible so that (unlike the case where friction must be put on almost continuously, as with a wheel), the friction can be made less than coextensive with (a) card length, and (b) ultimate container width. In other words, there is the novel provision of spaces (as at 55 in FIG. 5) between desired striking surfaces. This adds to the artistry of the final product and, can result in an annual saving of as much as $10,000 since it avoids having friction continually dulling cutting blades.

In usual manner (except without friction dulling of blades) the stock 12" of FIG. 5 is cut into cards, the cards are cut, combs of matches are inserted, and lastly the covers are folded to form individual match books. As seen in the perspective view of FIG. 6, a finished match book 61 then not only has the usual art work 53 but has a striking surface 54 which is less than coextensive with the measurements of the book in every measurable direction.

There is thus provided apparatus, article, method and composition of the class described capable of meeting the object of the invention. Even aside from the prior knife blade dulling (and consequent down time for sharpening or replacement due to continually cutting friction ma terial) the improved means of the invention has led to important savings because it has permitted friction ap plication to container stock at a rate more than eight times as fast as that known heretofore. Also, there have been added savings because of better quality control (greater precision control over thickness of friction application, straight edges, and the like), as well as improved appearance, and improved resistance to moisture.

While we have illustrated and described particular embodiments, various modifications may obviously be made without departing from the true spirit'and scope of the invention which we intend to have defined only by the appended claims taken with all reasonable equivalents.

We claim: 1. The method of applying a match striking surface to a paperboard container stock whereby to provide such a surface upon a container for matches, which method comprises the steps of:

forming a relatively fast drying relatively viscous match striking coating composition of a viscosity of about 1030 seconds #4 Zahn cup at 70 F.,

providing a rotogravure press cylinder with intaglio etchings substantially all of which are at least .005 inch deep,

applying said coating composition to said intaglio etchings,

and transferring said coating composition from said intaglio etchings to spaced areas of the paperboard container stock.

2. The method of claim 1 further characterized by the coating composition initially consisting of solids and nonaqueous liquid, said methodincluding the further step of rapidly drying the coating composition transferred to the paperboard container stock thereby removing said non-aqueous liquid, the resulting dried coating having a thickness of about .001-.003.

3. ,The method of claim 2 further characterized by providing the press cylinder with intaglio etchings forming relatively deep cells all of which are of a uniform depth of at least .005" and which in the image areas of the cylinder have a ratio of cell wall thickness to cell width in the range of 121.5 to 1:10 whereby to provide good definition While having the cell walls substantially uniformly spaced in the image areas at a rate of from 20 to 70 walls per inch to provide cells that are relatively wide and shallow relative to such width and that are separated by relatively narrow cell walls.

4. A rotogravure method of applying a match-striking surface to paperboard match-container stock by use of a rotogravure press cylinder with intaglio cells, which method includes the steps of:

forming a fast-drying relatively viscous and water-insoluble match-striking coating composition comprising synthetic resin, organic solvent therefor and match-striking solids;

filling said intaglio cells of said press cylinder with said coating composition, thereby forming discrete masses of said composition in said cells;

pressurally transferring said discrete masses from said intaglio cells of said press cylinder to discrete areas of said paperboard container stock, spreading such discrete masses into a continuous film of uniform thickness throughout each discrete area and rapidly drying the coating composition to remove the organic solvent therefrom to produce, on the paperboard stock, match-striking films, one in each of such discrete areas thereof; and

controlling the rotogravure application of said coating composition to said paperboard stock to effect such spreading of the discrete masses of coating composition into a continuous match-striking film of uniform thickness throughout each discrete area which when dried is free of hills and valleys and of a dried thickness of about .001-.003" by employing a coating composition of an initial viscosity of about 10-30 seconds #4 Zahn cup at 70 F. and by employing side-by-side quadrilateral intaglio cells of a depth of at least .005" with the cells being separated by cell walls and the ratio of cell wall thickness to cell width being in the range of about 1:15 to 1:10 with the cell walls spaced about 20-70 walls per inch. 5. A method for the high speed application of matchstriking surfaces to a strip of paperboard container stock in areas spaced laterally thereof and which strip is later cut along longitudinal lines between such areas and along lines transverse to the strip to form book match covers, which method includes the steps of:

forming a fast-drying match-striking coating composition comprising solids and non-aqueuos liquid with such coating composition having a viscosity of about -30 seconds #4 Zahn cup at 70 F.;

providing a rotogravure press cylinder with intaglio etchings in surface areas thereof spaced correspondingly to said areas of said paperboard stock;

filling said intaglio etchings with said coating composition and transferring the coating composition therefrom to said stock in said spaced areas thereof while advancing such stock in contact with the cylinder during rotation of the latter;

rapidly drying said coating composition thus transferred to said stock in such spaced areas thereof to evaporate said non-aqueous liquid and produce dried match-striking surfaces in such areas; and controlling the depth and width of said intaglio etchings with relation to the viscosity of said match-striking coating composition to produce dried match-striking surfaces free of hills and valleys and of a uniform thickness of about .001.003" by employing intaglio etchings forming cells of a depth of about .005-.010 and of a width, measured in the image area plane of the cylinder, several times such depth.

6. A method as defined in claim 5 in which such rotogravure application of said coating composition is controlled to produce match-striking films in said discrete areas of a dried uniform thickness of about .002" by employing 2070 cells per inch, the cell wall width to cell width ratio being between about 121.5 and 1:10.

7. A method as defined in claim 5 in which the solids content of said fast-drying match-striking coating composition comprises about 25-50% acrylic polymer binder and red phosphorous as an igniter, the igniter weight percent being at least that of the binder, the non-aqueous liquid being an organic solvent for said acrylic polymer, the amount of said organic solvent being suflicient to bring the viscosity of the coating composition within the range of 10-30 seconds #4 Zahn cup at 70 F.

References Cited UNITED STATES PATENTS 1,671,948 5/1928 Hutchinson 206-29 1,763,763 6/1930 Denmead 20629 2,683,098 7/1954 Sinks 117111 3,036,927 5/1962 Jerothe 118212 3,198,111 8/1965 Ellis et al. l01l70 ALFRED L. LEAVITT, Primary Examiner.

E. B. LIPSCOMB, Assistant Examiner. 

1. THE METHOD OF APPLYING A MATCH STRIKING SURFACE TO A PAPERBOARD CONTAINER STOCK WHEREBY TO PROVIDE SUCH A SURFACE UPON A CONTAINER FOR MATCHES, WHICH METHOD COMPRISES THE STEPS OF: FORMING A RELATIVELY FAST RELATIVELY VISCOUS MATCH STRIKING COATING COMPOSITION OF A VISCOSITY OF ABOUT 10-30 SECONDS #4 ZAHN CUP AT 70*F., PROVIDING A ROTOGRAVURE PRESS CYLINDER WITH INTAGLIO ETCHINGS SUBSTANTIALLY ALL OF WHICH ARE AT LEAST .005 INCH DEEP, APPLYING SAID COATING COMPOSITION TO SAID INTAGLIO ETHCINGS, AND TRANSFERRING SAID COATING COMPOSITION FROM SAID INTAGLIO ETCHINGS TO SPACED AREAS OF THE PAPERBOARD CONTAINER STOCK. 